Our immediate goal is to establish general methods for the syntheses of new silicones with low levels of toxicity. The overall aim is to create a higher degree of flexibility in the selection of silicone materials for biomedical applications. We therefore, propose studies in three promising areas: (1) silicone from cyclic ethers and silyl halides, (2) silicones from addition of silicon-silicon moieties across carbon-carbon multiple bonds and (3) silicones from addition of silicon-carbon moieties across carbon-oxygen multiple bonds. Our goal in the first area is to determine the mode of cleavage of ethers by silyl halides. In the second and third areas we seek to discover elusive intermediates in which silicon is involved in multiple (p-p) bonding. Recognition of the key intermediates, particularly those with silicon multiple bonds, will undoubtedly enhance our understanding of the course of many classical reactions which traditionally have afforded many silicone compounds. We also seek to establish a correlation between the structure of carbon-functional silicones and their physiological properties.